Add a couple of information functions to support direct checks on whether

a schema is our own temp schema or another backend's temp schema, and use
these in place of some former kluges in information_schema.  Per my
proposal of yesterday.

doc/src/sgml/func.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.336 2006/09/10 19:03:57 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.337 2006/09/14 22:05:05 tgl Exp $ -->
 
  <chapter id="functions">
   <title>Functions and Operators</title>
@@ -9232,6 +9232,18 @@ select current_date + s.a as dates from generate_series(0,14,7) as s(a);
        <entry>port of the local connection</entry>
       </row>
 
+      <row>
+       <entry><literal><function>pg_my_temp_schema</function>()</literal></entry>
+       <entry><type>oid</type></entry>
+       <entry>OID of session's temporary schema, or 0 if none</entry>
+      </row>
+
+      <row>
+       <entry><literal><function>pg_is_other_temp_schema</function>(<type>oid</type>)</literal></entry>
+       <entry><type>boolean</type></entry>
+       <entry>is schema another session's temporary schema?</entry>
+      </row>
+
       <row>
        <entry><literal><function>pg_postmaster_start_time</function>()</literal></entry>
        <entry><type>timestamp with time zone</type></entry>
@@ -9343,6 +9355,24 @@ SET search_path TO <replaceable>schema</> <optional>, <replaceable>schema</>, ..
      Unix-domain socket.
    </para>
 
+   <indexterm zone="functions-info">
+    <primary>pg_my_temp_schema</primary>
+   </indexterm>
+
+   <indexterm zone="functions-info">
+    <primary>pg_is_other_temp_schema</primary>
+   </indexterm>
+
+   <para>
+    <function>pg_my_temp_schema</function> returns the OID of the current
+    session's temporary schema, or 0 if it has none (because it has not
+    created any temporary tables).
+    <function>pg_is_other_temp_schema</function> returns true if the
+    given OID is the OID of any other session's temporary schema.
+    (This can be useful, for example, to exclude other sessions' temporary
+    tables from a catalog display.)
+   </para>
+
    <indexterm zone="functions-info">
     <primary>pg_postmaster_start_time</primary>
    </indexterm>

src/backend/catalog/information_schema.sql

@@ -4,7 +4,7 @@
  *
  * Copyright (c) 2003-2006, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/backend/catalog/information_schema.sql,v 1.36 2006/09/05 21:08:35 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/catalog/information_schema.sql,v 1.37 2006/09/14 22:05:06 tgl Exp $
  */
 
 /*
@@ -644,7 +644,8 @@ CREATE VIEW columns AS
     WHERE a.attrelid = c.oid
           AND a.atttypid = t.oid
           AND nc.oid = c.relnamespace
-          AND (nc.nspname NOT LIKE 'pg!_temp!_%' ESCAPE '!' OR pg_catalog.pg_table_is_visible(c.oid))
+          AND (NOT pg_is_other_temp_schema(nc.oid))
+
           AND a.attnum > 0 AND NOT a.attisdropped AND c.relkind in ('r', 'v')
 
           AND (pg_has_role(c.relowner, 'USAGE')
@@ -940,7 +941,7 @@ CREATE VIEW key_column_usage AS
                 AND nc.oid = c.connamespace
                 AND c.contype IN ('p', 'u', 'f')
                 AND r.relkind = 'r'
-                AND (nr.nspname NOT LIKE 'pg!_temp!_%' ESCAPE '!' OR pg_catalog.pg_table_is_visible(r.oid))
+                AND (NOT pg_is_other_temp_schema(nr.oid))
                 AND (pg_has_role(r.relowner, 'USAGE')
                      OR has_table_privilege(c.oid, 'SELECT')
                      OR has_table_privilege(c.oid, 'INSERT')
@@ -1467,7 +1468,7 @@ CREATE VIEW sequences AS
     FROM pg_namespace nc, pg_class c
     WHERE c.relnamespace = nc.oid
           AND c.relkind = 'S'
-          AND (nc.nspname NOT LIKE 'pg!_temp!_%' ESCAPE '!' OR pg_catalog.pg_table_is_visible(c.oid))
+          AND (NOT pg_is_other_temp_schema(nc.oid))
           AND (pg_has_role(c.relowner, 'USAGE')
                OR has_table_privilege(c.oid, 'SELECT')
                OR has_table_privilege(c.oid, 'UPDATE') );
@@ -1698,7 +1699,7 @@ CREATE VIEW table_constraints AS
     WHERE nc.oid = c.connamespace AND nr.oid = r.relnamespace
           AND c.conrelid = r.oid
           AND r.relkind = 'r'
-          AND (nr.nspname NOT LIKE 'pg!_temp!_%' ESCAPE '!' OR pg_catalog.pg_table_is_visible(r.oid))
+          AND (NOT pg_is_other_temp_schema(nr.oid))
           AND (pg_has_role(r.relowner, 'USAGE')
                -- SELECT privilege omitted, per SQL standard
                OR has_table_privilege(r.oid, 'INSERT')
@@ -1731,7 +1732,7 @@ CREATE VIEW table_constraints AS
           AND a.attnum > 0
           AND NOT a.attisdropped
           AND r.relkind = 'r'
-          AND (nr.nspname NOT LIKE 'pg!_temp!_%' ESCAPE '!' OR pg_catalog.pg_table_is_visible(r.oid))
+          AND (NOT pg_is_other_temp_schema(nr.oid))
           AND (pg_has_role(r.relowner, 'USAGE')
                OR has_table_privilege(r.oid, 'SELECT')
                OR has_table_privilege(r.oid, 'INSERT')
@@ -1806,7 +1807,7 @@ CREATE VIEW tables AS
            CAST(c.relname AS sql_identifier) AS table_name,
 
            CAST(
-             CASE WHEN nc.nspname LIKE 'pg!_temp!_%' ESCAPE '!' THEN 'LOCAL TEMPORARY'
+             CASE WHEN nc.oid = pg_my_temp_schema() THEN 'LOCAL TEMPORARY'
                   WHEN c.relkind = 'r' THEN 'BASE TABLE'
                   WHEN c.relkind = 'v' THEN 'VIEW'
                   ELSE null END
@@ -1823,7 +1824,7 @@ CREATE VIEW tables AS
                 THEN 'YES' ELSE 'NO' END AS character_data) AS is_insertable_into,
            CAST('NO' AS character_data) AS is_typed,
            CAST(
-             CASE WHEN nc.nspname LIKE 'pg!_temp!_%' ESCAPE '!' THEN 'PRESERVE'
+             CASE WHEN nc.oid = pg_my_temp_schema() THEN 'PRESERVE' -- FIXME
                   ELSE null END
              AS character_data) AS commit_action
 
@@ -1831,7 +1832,7 @@ CREATE VIEW tables AS
 
     WHERE c.relnamespace = nc.oid
           AND c.relkind IN ('r', 'v')
-          AND (nc.nspname NOT LIKE 'pg!_temp!_%' ESCAPE '!' OR pg_catalog.pg_table_is_visible(c.oid))
+          AND (NOT pg_is_other_temp_schema(nc.oid))
           AND (pg_has_role(c.relowner, 'USAGE')
                OR has_table_privilege(c.oid, 'SELECT')
                OR has_table_privilege(c.oid, 'INSERT')
@@ -1952,7 +1953,7 @@ CREATE VIEW triggers AS
           AND c.oid = t.tgrelid
           AND t.tgtype & em.num <> 0
           AND NOT t.tgisconstraint
-          AND (n.nspname NOT LIKE 'pg!_temp!_%' ESCAPE '!' OR pg_catalog.pg_table_is_visible(c.oid))
+          AND (NOT pg_is_other_temp_schema(n.oid))
           AND (pg_has_role(c.relowner, 'USAGE')
                -- SELECT privilege omitted, per SQL standard
                OR has_table_privilege(c.oid, 'INSERT')
@@ -2150,7 +2151,7 @@ CREATE VIEW views AS
 
     WHERE c.relnamespace = nc.oid
           AND c.relkind = 'v'
-          AND (nc.nspname NOT LIKE 'pg!_temp!_%' ESCAPE '!' OR pg_catalog.pg_table_is_visible(c.oid))
+          AND (NOT pg_is_other_temp_schema(nc.oid))
           AND (pg_has_role(c.relowner, 'USAGE')
                OR has_table_privilege(c.oid, 'SELECT')
                OR has_table_privilege(c.oid, 'INSERT')

src/backend/catalog/namespace.c

@@ -13,7 +13,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/catalog/namespace.c,v 1.86 2006/07/14 14:52:17 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/catalog/namespace.c,v 1.87 2006/09/14 22:05:06 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -143,6 +143,8 @@ Datum		pg_function_is_visible(PG_FUNCTION_ARGS);
 Datum		pg_operator_is_visible(PG_FUNCTION_ARGS);
 Datum		pg_opclass_is_visible(PG_FUNCTION_ARGS);
 Datum		pg_conversion_is_visible(PG_FUNCTION_ARGS);
+Datum		pg_my_temp_schema(PG_FUNCTION_ARGS);
+Datum		pg_is_other_temp_schema(PG_FUNCTION_ARGS);
 
 
 /*
@@ -2035,3 +2037,17 @@ pg_conversion_is_visible(PG_FUNCTION_ARGS)
 
 	PG_RETURN_BOOL(ConversionIsVisible(oid));
 }
+
+Datum
+pg_my_temp_schema(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_OID(myTempNamespace);
+}
+
+Datum
+pg_is_other_temp_schema(PG_FUNCTION_ARGS)
+{
+	Oid			oid = PG_GETARG_OID(0);
+
+	PG_RETURN_BOOL(isOtherTempNamespace(oid));
+}

src/include/catalog/catversion.h

@@ -37,7 +37,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.355 2006/09/10 00:29:34 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.356 2006/09/14 22:05:06 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	200609091
+#define CATALOG_VERSION_NO	200609141
 
 #endif

src/include/catalog/pg_proc.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.423 2006/09/10 00:29:34 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.424 2006/09/14 22:05:06 tgl Exp $
  *
  * NOTES
  *	  The script catalog/genbki.sh reads this file and generates .bki
@@ -3096,6 +3096,10 @@ DATA(insert OID = 2083 (  pg_opclass_is_visible		PGNSP PGUID 12 f f t f s 1 16 "
 DESCR("is opclass visible in search path?");
 DATA(insert OID = 2093 (  pg_conversion_is_visible	PGNSP PGUID 12 f f t f s 1 16 "26" _null_ _null_ _null_ pg_conversion_is_visible - _null_ ));
 DESCR("is conversion visible in search path?");
+DATA(insert OID = 2854 (  pg_my_temp_schema			PGNSP PGUID 12 f f t f s 0 26 "" _null_ _null_ _null_ pg_my_temp_schema - _null_ ));
+DESCR("get OID of current session's temp schema, if any");
+DATA(insert OID = 2855 (  pg_is_other_temp_schema	PGNSP PGUID 12 f f t f s 1 16 "26" _null_ _null_ _null_ pg_is_other_temp_schema - _null_ ));
+DESCR("is schema another session's temp schema?");
 
 DATA(insert OID = 2171 ( pg_cancel_backend		PGNSP PGUID 12 f f t f v 1 16 "23" _null_ _null_ _null_ pg_cancel_backend - _null_ ));
 DESCR("Cancel a server process' current query");